Patent GB-402946-A (GB)
Title: Improvements in or relating to a method of dispersing solids
IPC: B01J13/00
Filed: 1933-01-04
Abstract: Dispersions of friable non-metallic substances having a melting point above the boiling point of water are obtained by melting the substances and chilling them in the form of moderately small pellets, which are then subjected to mechanical disintegration, preferably in a colloid mill, in the presence of a dispersing fluid.  The dispersing fluid is preferably water containing a dispersing agent, such as casein, gelatine, albumen, soap, sulphonated oils, saponin, or water glass.  The pellets range from one-fourth inch in diameter to particles which are just retained by a 100 mesh sieve, preferably particles of sizes from about 8 to 20 mesh.  If the substance to be dispersed is readily fusible, it is prepared by melting it and pouring the hot liquid through a screen or sieve into cold water. Suitable substances to be treated include sulphur, mercaptobenzthiazole, natural hard resins and glass.  According to an example, 100 parts sulphur prepared in globules of from 8 to 10 mesh size are stirred into a solution of equal parts of gelatine and casein in 65 parts of slightly alkaline water, and then treated in a colloid mill of the high-speed, small clearance type.  The mill may contain a single rotor and stator or a pair of oppositely rotating rotors with either smooth or fluted working faces, e.g. about 6 in. diameter rotating at 3600 r.p.m. with a clearance of from 2 to 5 thousandths of an inch.  The mixture is circulated through the mill, the temperature being maintained below 60 DEG  C., and then through a cooling device in a continuous cycle.  The concentration of the dispersion is about 60 per cent sulphur, and the average particle size about 0.3m , with a maximum size of 1m .  About 10 per cent of the sulphur settles on standing, and is separated off and treated again.  This dispersion may be diluted with pure water and may be mixed with other alkaline dispersions including natural or artificial rubber latex in any desired proportions.  It may also be used as a fungicide.  Specification 24437/09, [Class 1 (i), Chemical processes &c.], is referred to.ALSO:Dispersions of friable non-metallic substances having a melting point above the boiling point of water are obtained by melting the substances and chilling them in the form of moderately small pellets, which are then subjected to mechanical disintegration, preferably in a colloid mill, in the presence of a dispersing fluid.  The dispersing fluid is preferably water containing a dispersing agent, such as casein, gelatine, albumen, soap, sulphonated oils, saponin or water glass.  The pellets range from one-fourth inch in diameter to particles which are just retained by a 100 mesh sieve, preferably particles of sizes from about 8 to 20 mesh.  If the substance to be dispersed is readily fusible, it is prepared by melting it and pouring the hot liquid through a screen or sieve into cold water.  Suitable substances to be treated include sulphur, mercaptobenzthiazole, natural hard resins and glass. According to an example, 100 parts sulphur prepared in globules of from 8 to 10 mesh size are stirred into a solution of equal parts of gelatine and casein in 65 parts of slightly alkaline water, and then treated in a colloid mill of the high-speed, small clearance type. The mill may contain a single rotor and stator or a pair of oppositely rotating rotors with either smooth or fluted working faces, e.g. about 6 in. diameter rotating at 3600 r.p.m. with a clearance of from 2 to 5 thousandths of an inch.  The mixture is circulated through the mill, the temperature being maintained below 60 DEG  C., and then through a cooling device in a continuous cycle. The concentration of the dispersion is about 60 per cent sulphur, and the average particle size about 0.3m  with a maximum size of 1m . About 10 per cent of the sulphur settles on standing, and is separated off and treated again.  This dispersion may be diluted with pure water and may be mixed with other alkaline dispersions including natural or artificial rubber latex in any desired proportions.  It may also be used as a fungicide.  Specification 24437/09, [Class 82 (i), Metals, Extracting &c.], is referred to.ALSO:Dispersions of friable non-metallic substances having a melting point above the boiling point of water are obtained by melting the substances and chilling them in the form of moderately small pellets, which are then subjected to mechanical disintegration, preferably in a colloid mill, in the presence of a dispersing fluid.  The dispersing fluid is preferably water containing a dispersing agent, such as casein, gelatine, albumen, soap, sulphonated oils, saponin or water glass. The pellets range from one-fourth inch in diameter to particles which are just retained by a 100 mesh sieve, preferably particles of sizes from about 8 to 20 mesh.  If the substance to be dispersed is readily fusible, it is prepared by melting it and pouring the hot liquid through a screen or sieve into cold water.  Suitable substances to be treated include sulphur, mercaptobenzthiazole, natural hard resins and glass.  According to an example, 100 parts sulphur prepared in globules of from 8 to 10 mesh size are stirred into a solution of equal parts of gelatine and casein in 65 parts of slightly alkaline water, and then treated in a colloid mill of the high-speed, small clearance type.  The mill may contain a single rotor and stator or a pair of oppositely rotating rotors with either smooth or fluted working faces e.g. about 6in. diameter rotating at 3600 r.p.m. with a clearance of from 2 to 5 thousandths of an inch.  The mixture is circulated through the mill, the temperature being maintained below 60 DEG  C., and then through a cooling device in a continuous cycle. The concentration of the dispersion is about 60 per cent sulphur, and the average particle size about 0.3m  with a maximum size of 1m . About 10 per cent of the sulphur settles on standing, and is separated off and treated again.  This dispersion may be diluted with pure water and may be mixed with other alkaline dispersions including natural or artificial rubber latex in any desired proportions. Specification 24437/09, [Class 82 (i), Metals, Extracting &c.], is referred to.